https://scholars.lib.ntu.edu.tw/handle/123456789/498114
DC 欄位 | 值 | 語言 |
---|---|---|
dc.contributor.author | Woon, K.-L. | en_US |
dc.contributor.author | Yi, C.-L. | en_US |
dc.contributor.author | Pan, K.-C. | en_US |
dc.contributor.author | Etherington, M.K. | en_US |
dc.contributor.author | CHUNG-CHIH WU | en_US |
dc.contributor.author | KEN-TSUNG WONG | en_US |
dc.contributor.author | Monkman, A.P. | en_US |
dc.creator | Woon, K.-L.;Yi, C.-L.;Pan, K.-C.;Etherington, M.K.;Wu, C.-C.;Wong, K.-T.;Monkman, A.P. | - |
dc.date.accessioned | 2020-06-11T06:15:58Z | - |
dc.date.available | 2020-06-11T06:15:58Z | - |
dc.date.issued | 2019 | - |
dc.identifier.issn | 19327447 | - |
dc.identifier.uri | https://scholars.lib.ntu.edu.tw/handle/123456789/498114 | - |
dc.description.abstract | Understanding the excited-state dynamics and conformational relaxation in thermally activated delayed fluorescence (TADF) molecules, including conformations that potentially support intramolecular through-space charge transfer, can open new avenues for TADF molecular design as well as elucidate complex photophysical pathways in structurally complex molecules. Emissive molecules comprising a donor (triphenylamine, TPA) and an acceptor (triphenyltriazine, TRZ) bridged by a second donor (9,9-dimethyl-9-10-dihydroacridin, DMAC, or phenoxazine, PXZ) are synthesized and characterized. In solution, the flexibility of the sp3-hybridized carbon atom in DMAC of DMAC-TPA-TRZ, compared to the rigid PXZ, allows significant conformational reorganization, giving rise to multiple charge-transfer excited states. As a result of such a reorganization, the TRZ and TPA moieties become cofacially aligned, driven by a strong dipole-dipole attraction between the TPA and TRZ units, forming a weakly charge-transfer dimer state, in stark contrast to the case of PXZ-TPA-TRZ where the rigid PXZ bridge only supports a single PXZ-TRZ charge transfer (CT) state. The low-energy TPA-TRZ dimer is found to have a high-energy dimer local triplet state, which quenches delayed emission because the resultant singlet CT local triplet energy gap is too large to mediate efficient reverse intersystem crossing. However, organic light-emitting diodes using PXZ-TPA-TRZ as an emitting dopant resulted in external quantum efficiency as high as 22%, more than two times higher than that of DMAC-TPA-TRZ-based device, showing the impact that such intramolecular reorganization and donor-acceptor dimerization have on TADF performance. © 2019 American Chemical Society. | - |
dc.relation.ispartof | Journal of Physical Chemistry C | - |
dc.subject.other | Charge transfer; Conformations; Dimerization; Dimers; Fluorescence; Molecules; Organic light emitting diodes (OLED); Synthesis (chemical); Charge transfer state; Conformational relaxation; Dipole-dipole attractions; Emissive molecules; Excited-state dynamics; External quantum efficiency; Inter-system crossings; Thermally activated delayed fluorescences; Excited states | - |
dc.title | Intramolecular Dimerization Quenching of Delayed Emission in Asymmetric D-D′-A TADF Emitters | en_US |
dc.type | journal article | en |
dc.identifier.doi | 10.1021/acs.jpcc.9b01900 | - |
dc.identifier.scopus | 2-s2.0-85065893103 | - |
dc.identifier.url | https://www.scopus.com/inward/record.uri?eid=2-s2.0-85065893103&doi=10.1021%2facs.jpcc.9b01900&partnerID=40&md5=0b3b163f07e87dc529aaef1c54e619f6 | - |
dc.relation.pages | 12400-12410 | - |
dc.relation.journalvolume | 123 | - |
dc.relation.journalissue | 19 | - |
item.openairecristype | http://purl.org/coar/resource_type/c_6501 | - |
item.openairetype | journal article | - |
item.grantfulltext | none | - |
item.cerifentitytype | Publications | - |
item.fulltext | no fulltext | - |
crisitem.author.dept | Electrical Engineering | - |
crisitem.author.dept | Office of Research and Development | - |
crisitem.author.dept | Chemistry | - |
crisitem.author.orcid | 0000-0002-1680-6186 | - |
crisitem.author.parentorg | College of Electrical Engineering and Computer Science | - |
crisitem.author.parentorg | Administrative Unit | - |
crisitem.author.parentorg | College of Science | - |
顯示於: | 電機工程學系 |
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